Ask the Experts about Jewelry Making

Topics: Pearls, formation, irregularities

Q.

I'm curious as to what exactly causes the lines which appear around some cultured freshwater pearls?

- Cheryl

A.

Cultured freshwater pearls are created after a freshwater mollusk is implanted with a small piece of organic matter. The mollusk naturally produces a substance, called nacre, around the organic matter or irritant, to protect itself. As the mollusk grows, so does the pearl. The lines you see on pearls indicate the layers of nacre.